Amirhossein Pahlevanpour - Sharif University of Technology
Hamed Salmani - Sharif University of Technology
Mohammad Ali Kouchakzadeh - Sharif University of Technology;

An isogrid lattice (Stiffener) is one potential method of improving the efficiency of cylindrical shell which made the structure lighter but more resistant against axial buckling. The isogrid lattice structure is consisting of a dense system of unidirectional ribs. Lattice structures can be made of metals or composite with no skin, a single-sided skin, or a double-sided skin. Composite isogrid lattice structures have so far found application in only a selected number of specialist applications like space and automotive industry. Buckling of a stiffened cylindrical shell is a very complex phenomenon that involves complex interactions between the skin and the stiffeners. Depending on different configurations of the skin and stiffener, different buckling failure modes (Including global and local failure) and critical buckling loads are observed in stiffened cylinders. But most of the time the most critical buckling load of these structures is the load which causes global buckling. So In this study global failure mode and buckling loads of stiffened composite cylinders with particular stiffener configuration (lozenge Structures) under uniaxial loading condition is investigated, first by using three different analytical approaches and second, the result of these approaches will be evaluated by a FEM based approach which was done by modeling this specific structure in ANSYS software. Finally, general conclusions are drawn regarding to different configurations of the effective design parameters of the grid stiffened cylinder.

Buckling, Isogrid, Lozenge, FEM